A cord is a long, slender, and flexible material that can take the form of many shapes and sizes, and be made of a large number of different materials. As used herein, cord encompasses wire, string, cable and a multitude of other variations and materials. Some cords have one beginning and one end. One example of such a cord is an electric appliance cord that can be removed from the appliance. One end has a plug for insertion into an electric mains and the other end is inserted into a jack (either female or male) on the appliance.
Other applications involve cords with more than one beginning and one end. Various telephone cords, for example, split after a certain length to connect two or more telephones to a telephone jack in the wall. Similarly, a number of television cords, whether using cable or satellite, split at certain points in order to transfer data to multiple television sets or to send signals to different channels, such as the L and R speaker channels. Another example is a cord used for electronic headphones. Such headphone cords extend from an electronic device to a listener's ears, allowing the listener to hear audio. These cords have been in existence for decades. Such electronic devices serve a myriad of purposes; examples include, but are not limited to, cassette players, Compact Disc/DVD players, and MP3 players. Some users choose to listen to music while exercising, while others listen to an electronic device throughout the day no matter what the task. Although commonly used for music, any audible sound can be played through the earphone cords. For instance, some students listen to lectures and other audible study aids utilizing these electronic devices.
In use, a listener inserts a male plug end of the headphone cord (e.g., a 3.5 mm male plug) into a corresponding female socket of the electronic device. After a certain length, the headphone cord splits into two separate cords, resulting in a “Y” configuration. These two ends are fitted with earphones that fit into or around a person's left and right ears. One example is the common earbud configuration. On some models, the earphone orientation is ear specific, whereas, in other models, the earphones are interchangeable between the user's left and right ears.
One of the drawbacks regarding existing headphone technology is the likelihood of the cords becoming intertwined. Mathematical studies of tangling reveal that cords become tangled because loose ends are allowed to snake into loops of the cord or because loops are allowed to snake into other loops. When an end travels through a loop as the cord twists and turns, knots are created. In the embodiment of headphones, when a user is not wearing the device, cord ends are unrestrained and free to move in any direction. While the headphones are stored, for instance, lying on a desk, in a drawer, or in a bag, to name a few, the free ends inevitably become intertwined and tangle. Once tangling occurs, a person is required to spend needless time and effort attempting to untangle the various ends. Moreover, once a person successfully untangles the headphone cords, there is nothing to prevent the cord ends from tangling yet again in the future. In addition, the tangling can result in knots, thereby creating kinks in the wires inside the cords and potentially damaging the operation of the headphones.
Placing a spool or similar retraction device in the middle of the wire does not solve the fundamental problem. A spool winds the cord around a cylinder. However, the ends of the headphones still remain unrestrained and free to intertwine. In addition, the winding of a headphone cord around a spool causes the cord to conform to the circular shape of the cylinder. Thus, when later unwound, a multitude of loops is created for the ends to travel through, representing a fertile breeding ground for tangling.
With the dramatic rise of electronic media packaged for consumers on the go, countless consumers are purchasing handheld electronic devices that require the use of headphones. It would, therefore, be desirable to provide a way of limiting the travel of the ends of headphone cords to prevent the occurrence of tangling and knots.